Body composition analysis: what the measurement tells you

A body composition analysis takes about 15 minutes and gives you numbers the scale alone never shows — body fat percentage, muscle mass, visceral fat in the abdominal cavity, daily calorie needs. Below I explain what these figures really mean and how to prepare for the measurement so the result is reliable.

What a body composition analysis actually shows

The principle is simple: a very weak current is sent through the body, and the device measures how quickly it travels between tissues. Muscle tissue conducts the current better and fat tissue conducts it worse — that difference is what allows the device to estimate body composition.

A typical report contains six or seven readings:

• Body fat percentage — how much of your body weight is fat tissue
• Muscle mass in kilos — a summary figure whose change is worth tracking
• Visceral fat — the fat around the internal organs in the abdominal cavity, and the most important one from a health standpoint
• Biological age — more of a motivational estimate than a strict metric
• Daily calories — your estimated basal metabolic requirement
• Body type — endomorph, ectomorph or mesomorph, again only a rough guide

Two numbers deserve special attention: visceral fat and muscle mass. They tell you something a bathroom scale simply can’t show. A person’s weight can stay the same over a year while muscle mass grows by 3 kg and body fat percentage drops — the scale lies, a body composition analysis doesn’t.

Who benefits from a body composition analysis

Honestly, almost anyone who trains with a purpose. But the measurement is especially useful in three situations.

When you’re starting to train. Your first measurement gives you a starting point to compare against after 6–8 weeks. Without a starting point there’s nothing to compare, and without a comparison you can’t know whether what you’re doing works.

When the scale is stuck but your body seems to be changing. This is a typical sign of recomposition — muscle replaces fat, but the scale stays where it was. A body composition analysis shows this pattern right away.

When your family doctor has been concerned about your body fat percentage. Visceral fat is directly linked to cardiovascular risk, and a home scale can’t show it. A measurement at your club at least gives you a rough picture of whether you’re heading in the right direction.

How to prepare for the measurement

Bioimpedance is sensitive to water balance — that’s why there are a few simple rules worth following.

• Don’t eat for 2–3 hours before the measurement. A full stomach distorts the result.
• Don’t drink too much water before the measurement, but don’t go thirsty either. A normal daily fluid level is fine.
• Leave training for after the measurement that day, not before it. Sweating and increased blood flow to the muscles change the reading.
• Alcohol the evening before rules out a reliable result — your body is dehydrated.
• In women, the menstrual cycle can shift water levels by a couple of kilos. If possible, measure in the same phase of the cycle.

You don’t need to wear sportswear; light clothing is fine. Some analyzers let you enter the weight of light clothing separately — always ask about this if it doesn’t come up automatically.

One important thing: always compare results from the same analyzer. Readings from two different devices may not match each other, even if both are calibrated.

FAQ: body composition analysis and results

How accurate is a body composition analysis, really?
Bioimpedance isn’t a research instrument but a trend tracker. A single number matters less than the change over time. Typical accuracy falls within a couple of percentage points, which is perfectly sufficient for everyday tracking.

How often should you get a body composition analysis?
Every 6–8 weeks is a good rhythm. Measure more often and you won’t see a change anyway — muscle mass grows slowly, over months. Measure less often and you lose the link between your training and the results.

What is a good body fat percentage?
It depends on age and sex. Roughly 10–20% is considered healthy for men and 18–28% for women. The athletic range is lower, but it isn’t sustainable at every stage of life. The more important question: is your body fat percentage falling, stable or rising over time?

Author: Sparta SS

Come and train! ArtGym